Caption: TRAPPIST-1 planetary tourism. Futuristic space tourism poster advertising a trip to the TRAPPIST-1 planetary system to see its seven planets. This view is from the fourth planet, TRAPPIST-1e. The ultra-cool dwarf star TRAPPIST-1 is 39 light years from Earth, in the constellation of Aquarius. Its planets were discovered in 2015 and 2017, and have been studied using NASA's Spitzer Space Telescope (SST) and the ground-based TRAPPIST (Transiting Planets and Planetesimals Small Telescope). TRAPPIST-1 is Jupiter-sized, and all the planets are close to the size of the Earth. They orbit as close as Mercury does to our Sun, completing their orbits in a few Earth days. Several of the planets may be in a habitable zone for life. Image published in 2017.